1. Field of the Invention
This invention relates to tube benders and in particular to manually operable tube benders wherein a forming member is swung about a mandrel bending axis by means of a handle associated therewith and a handle mounted to the mandrel.
2. Description of the Background Art
Manually operable tube benders are well known in the art. One improved form of such tube bender is illustrated in U.S. Pat. No. 2,796,785 of Howard L. Philippe. As shown therein, a shoe forming member is provided with a handle. The shoe is swingably mounted to a mandrel for pivotal movement about a bending axis. A second handle is connected to the mandrel. A hook is swingably mounted on the second handle for engaging the tube at a point adjacent the bend start point of a groove in the periphery of the mandrel into which the tube is urged in the bending operation. A scale is provided on the mandrel and a cooperating indicating mark is provided on the shoe.
Further improved tube benders are illustrated in U.S. Pat. Nos. 2,887,917 and 3,926,028 of the inventor herein. In U.S. Pat. No. 2,887,917, a tube bender is illustrated wherein the handle connected to the mandrel is provided with an offset and improved scale means are provided on the mandrel for indicating the extent of the formed bend. Three cooperating scale means are provided, including an angular scale on the mandrel, a scale extending from a point on the mandrel aligned with the cross-sectional center of the tube receiving space, and a mark on the mandrel at a predetermined distance from the bend start point.
In Kowal U.S. Pat. No. 3,926,028, the tube bender is provided with a vise mounting portion in lieu of the handle secured to the mandrel. In one form, the hook is formed integrally with the male clamp portion, and in a second form, the hook is pivotally mounted thereon. A scale is provided on the mandrel and a plurality of cooperating indicia are provided on the shoe.
In U.S. Pat. No. 3,750,447 of the inventor herein and William R. Saddler, a further improved tube bender is illustrated having fixed hook means with a cutout space being provided in confrontation to the hook to permit facilitated installation of the tube to be bent into the tool, notwithstanding the fixed relationship of the hook to the mandrel. Cooperating scale means on the mandrel and indicator means on the shoe are provided for indicating the angular extent of the bend.